Throttling valve



Jan. 3, 1956 N. H: coLLlNs 2,729,069

THROTTLING VALVE Filed April 13, 1953 INVENTOR. MMM/'w H, wu/v5 THROTTLING VALVE Norman H. Collins, Flushing, N. Y. Application April 13, 1953, Serial No. 348,451

3 Claims. (Cl. 62-8) This application includes the species included in the abandoned application Ser. No. 666,758, iiled May 2, 1946.

This invention relates to a throttling valve and more particularly to a throttling valve used in a refrigeration system.

In refrigeration systems there is a circulation of a refrigerant gas and the gas is condensed to a liquid and recirculated through a throttling valve. The liquid that is passed by the expansion valve is first passed through a restrictor into an expansion chamber or evaporator, where it expands and again becomes a gas. The control of pressure for operating the throttling valve is rather critical, there has been a great deal of trouble with the throttling valves used in the past, due to their inaccuracy in operation.

It is an object of this invention to provide a throttling valve that will open, while a predetermined back pressure force is acting on one side of the valve, by the force of the liquid in the opposite direction.

It is a further object of this invention to provide an expansion valve that will open with a predetermined pressure on one side of the valve and having opened the uid pressure will maintain it open, the same pressure acting on a larger area provides a greater force to maintain the valve open.

Another object of this invention is to provide an expansion valve in which a predetermined force is utilized to maintain the valve closed and in which the back pressure of the system will overcome this force maintaining the valve closed, to open the valve and restore circulation in the valve.

A further object of this invention is to provide a throttling valve in which a predetermined pressure on a ball valve will open said valve, while the predetermined pressure acts on a larger area piston to maintain said valve open.

A still further object of this invention is to provide a throttling valve comprised of a ball valve, a holding piston and a reseating piston which is opposed to the ball valve and holding piston and is of much greater area to be acted upon by the back pressure of the refrigerant system.

Another object of this invention is to provide a throttling valve having a ball valve maintained closed by the back pressure of the refrigerant system and in which the refrigerant liquid pressure opens said ball valve and maintains said ball valve open and in which the refrigerant liquid continuously thereafter is evaporated into the refrigerant system to build up a back pressure of a predetermined amount to reclose said ball valve controlling the ingress of refrigerant liquid.

Other objects may be apparent by reference to the accompanying description and the drawings in which:

Fig. 1 illustrates a cross sectional View of the throttling valve and schematically illustrates its manner of inclusion in a refrigerant system,

nited States Patent O rice Fig. 2 illustrates another embodiment of the valve illustrated in Fig. 1,

Fig. 3 illustrates a cross sectional view of another embodiment of the throttling valve connected to a refrigerant system that is illustrated schematically.

Referring to Fig. 1 there is illustrated a valve 9 composed of a housing 10 having two bores 11 and 12 in which a reciprocating piston 14 is provided and is comprised of two portions of diiferent diameter to correspond with the bores 11 and 12 in which they are mounted. The piston 14 is provided with seals 15 and 16 to give a sealing eifect when the piston is reciprocated in the bores 11 and 12. The piston 14, on one face thereof, is provided with a concave section 17 which bears against a ball valve 18. The ball valve 18, in turn, is seated against a valve seat 19 which, in this instance, has been secured to the housing 10. A port 20 is provided below the ball valve 18 through the seat member 19. The piston 14 on its opposite face is provided with a bore 21, which is threaded to receive a restrictor 22. The restrictor 22 having a restricting aperture 23 and an enlarged evaporator bore 24. The piston 14 further has a connecting channel 25 which connects with a channel 26 which, in turn, connects with the exterior of the small end of the the piston 14. A threadably secured plug 28 is provided to be secured in the large bore 12 and restricts the reciprocating movement of the piston 14. The plug 28 is provided with a central bore 29 in which a spring 30 is mounted to bear against the face of the piston 14 at one end and to bear against an adjustable threaded member 35 that is threadably secured to the plug 28 at its other end. The member 30 is provided with a lock nut 31 for maintaining a setting. The plug 2 is further provided with a channel 32 which is connected to an outlet port 33. In Fig. l the throttling valve is illustrated schematically connected through port 33 to a compressor 40 by means of a tube 41. The output of the compressor 4t) is connected to a condenser 42 by means of a tube 43 and the condenser, at its outlet port 44, is connected by means of a tube 45 to the inlet port 2@ of the throttling valve.

The operation of the device illustrated in Fig. l may be followed by referring to the numerals and parts now designated in Fig. 1. The condenser 42 and compres sor 40 will supply a liquid under 100 p. s. i. through the tube 45 to the port 20 and, if the area of the ball valve seat 19 is .1019", the liquid pressure will be 1.9 pounds on the area of the ball valve 18, thus producing p. s. i. on the area of the small piston in the bore i1.. 1f this area is .062 a force of 6.2 pounds will be produced on the piston 14 holding the valve open. The liquid entering bore 11 will pass through channels 2e' and 25 through the aperture 23 and be evaporated through bore 24 and bore 29 passing through the bore 12 to the tube 41 to the compressor 40. However, a back pressure will be built up and will be effective over the larger diameter of the piston 14. In the event the larger area of the piston 14 is .441" it will be necessary for the back pressure to exceed 14.1 p. s. i. to effect a closing of the valve. ln other words, it will be necessary to build up a back pressure of 14.1 p. s. i. to overcome the 100 p. s. i. still effective on the opposite end or smaller end of the piston 14. When the back pressure on piston 14 has exceeded a value of 14.1 p. s. i. it will cause the piston to return the ball valve 18 to the valve seat 19, thus the refrigerant pressure will then become equalized by means of the restrictor orifice or the capillary tube. lt is apparent that when the ball valve 18 has been seated on the valve seat 19 that the effective area on which the force may act in an opposite direction to the closing force has been reduced from .062, the small piston area, to .019, the port area. This reduction of the area on which the pressure is acting permits an effective positive sealing of the ball valve by the back pressure until the back pressure has been reduced to a predetermined minimum at which time the valve is again ready for its next cycle of operation. The back pressure differential may be increased or decreased by using various springs, of varying rate, or by modifying the relative areas. The spring 30 has been shown with the adjustable member 35, in this embodiment this spring being primarily to permit adjusting the valve to a vacuum, and any force that may be predetermined in the design of the spring and in its adjustment necessarily changes the operating pressures already stated for this valve under the conditions and areas given. However, it is apparent that in the example stated the valve will open when 1.9 pounds operates on the ball valve and will remain open as long as the pressure does not exceed 14.1 pounds pressure on the larger piston. When the valve has closed it will remain closed as long as the back pressure does not drop below 4.77 p. s. i. on the larger area of the piston 14.

Referring to Fig. 2 there is illustrated another embodiment of valve 9 that is similar to that illustrated in Fig. l except that the restrictor 22 is replaced with a solid plug 22A and the bore 11 is connected to a capillary tube 36. The capillary tube 36 should be connected to bore 11 in the area of the ball valve 18. The throttling valve 9 is illustrated schematically connected to an evaporator 38 and the evaporator is in turn connected by a tube 39 to an inlet port 34 of the valve, the port 34 is in turn connected to the channel 32 of the plug 28. The operation of the valve is somewhat similar to the operation of the valve as illustrated in Fig. 1. With the 100 p. s. i. produced in bore 11, this fluid pressure will ilow through the capillary tube 36 and be evaporated in the evaporator 38, the evaporated fluid will pass through tube 39 into channel 32, and will be recirculated. The liquid entering the capillary tube 36 will expand and will further expand or evaporate in the evaporator 38. However, even with the expansion there will be a build-up of back pressure that is effective over the larger diameter of the piston 14. When the back pressure exceeds 14.1 p. s. i. it will effect a closing of the ball valve by means of the movement of piston 14.

Referring to Fig. 3, there is illustrated a further embodiment of this invention which is the same valve structure as illustrated in Fig. 1 and in which the housing 16 is provided with the same bores 11 and 12 and the same piston 14 and the ball valve 18. In this particular embodiment (illustrated in Fig. 3) the evaporator 38 will be connected directly to the port 32 and the evaporator in turn, will be connected to the tube 41 and thus to the compressor 40 and to the condenser 42 and the condenser Will in turn be connected by means of the tube 45 to the inlet port 20 of the Valve. Thus this embodiment is similar to the embodiment shown in Fig. 1 except that the evaporator has been introduced between the valve and the compressor. In this embodiment the deletion of the spring is permissible as long as the back pressure in the system remains above 3 p. s. i. and in this embodiment the adjustable feature of the adjusting means 35 is no longer effective. Further, in this embodiment, the liquid passing the ball valve 18 will pass through the channels 26 and 25 to the restrictor 23 and will expand in the bore 24 into the chamber 29 and the bore 12, as a gas, passing through the port 32 into the evaporator 38 where it is passed to the compressor and pumped through the condenser 42 to be restored to its liquid form and is again ready to be recirculated back to the port 20.

Referring to Fig. 1 it is apparent that the amount of modulation of the valve is controlled by the areas of the ball valve seat, the small area of the piston and the large area of the piston 14 as well as the pressure exerted by spring 30 (in Fig. l). Likewise, the negative pressure on one side of piston 14 may be controlled by the spring 30 (in Figs. 1 and 2) while the positive pressure acts on the opposite side of piston 14 and is effective on the small end and in turn the large end of the piston 14. In the other embodiment (Fig. 3), the amount of modulation is controlled by the effective relative areas of the large and small ends of the piston 14 and the seat 19. In spite of the large difference in the areas of seat 19 and large end of piston 14 the force acting on ball 18 will not effect closing by back pressure on 14 to an extent that will cause said back pressure to become excessive, in case of higher inlet pressures and conversely not to become too low in case of low inlet pressures.

The restrictor 22 is shown as removable in Fig. 1 to allow the insertion of a desirable size restriction instead of an adjustable restrictor. The capillary tube 36 may be used to obtain the same general result and when used the end of the tube 36 should be inserted into or adjacent to the evaporator 38. The restrictor 22 as illustrated is rather exaggerated whereas actually the restriction shall be quite small to insure the expansion of the liquid passing therethrough.

Various modifications and changes in the device illustrated may be made without departing from the spirit of this invention and this invention shall be limited only by the appended claims.

What is claimed is:

1. A refrigerant throttling valve including, a valve housing having two bores of different size, a movable piston member composed of two portions that approximate the cross sectional areas of the two bores and into which it is mounted, a valve seat in the housing facing the smaller of the two bores, and providing an inlet port, a ball valve mounted between the valve seat and the face of the smaller portion of the piston to open or close said port, a pair of seals one about the periphery of each of the two portions of the piston, a restrictor connected at one end to the smaller face of the piston and connected at the other end to the larger face of the piston, a closure element mounted in the larger bore of the housing to restrict the movement of the piston and to form an expansion chamber for the restrictor, and a port to connect said expansion chamber to the suction side of a compressor.

2. A refrigerant throttling valve including, a housing having two bores of different size, a movable piston member composed of two portions that approximate the cross sectional areas of the two bores and into which it is mounted, a valve seat in the housing facing the smaller of the two bores and providing an inlet port, a ball valve mounted between the valve seat and the face of the smaller portion of the piston, to open or close said port, a pair of seals one about the periphery of each of the two portions of the piston, a restrictor connected at one end to the smaller face of the piston and connected at the other end to the larger face of the piston, a closure element mounted in the larger bore of the housing to restrict the movement of the piston and to form an expansion chamber for the restrictor, a port to connect said expansion chamber to the suction side of a compressor, a resilient means mounted between the said closure element and the larger face of said piston, and means to adjust the amount of force exerted by said resilient means.

3. A refrigerant throttling valve including, a valve housing having two bores of different size, a movable piston member composed of two portions that approximate the cross sectional areas of the two bores and into which it is mounted, a valve seat in the housing facing the smaller of the two bores, and providing an inlet port, a ball valve mounted between the Valve seat and the face of the smaller portion of the piston to open or close said port, a pair of seals one about the periphery of each of the two portions of the piston, a restrictor connected at one end to the smaller face of the piston and connected at the other end of the larger face of the piston, a closure element mounted in the larger bore of the housing to restrict the movement of the piston and to form an expansion chamber for the restrictor, an evaporator connected to said expansion chamber, said evaporator connected to the suction side of a compressor, a resilient means mounted between the said closure element and the larger face of said piston, and means to adjust the amount of force exerted by said resilient means.

References Cited in the le of this patent UNITED STATES PATENTS 2,163,799 Nevin June 27, 1939 2,291,033 Goepfrich July 28, 1942 2,326,093 Carter Aug. 3, 1943 

